Automatic fire



FIA. SWAN AUTOMATIC F1115. ALARM. APPLICATIONHLEU JULY 2. 191,1.

@ Patented Deo, 30,1919.

. instaan. santas Partnr onirica FREDERICK A. SWAN,A OF CLIFTONDALE, MASSACHUSETTS.

AUTOMATIC rias-ALARM.

Specification of Letters Patent.

Patented Dec. 30, QQ.

Application filed July 2, 1917.v Serial No. 178,121.

To au whom t may concern.' l

Be it known that LFnnnnnion A. Swan,

a .citizen 'of the Unit/ed States, residing at Cliftondale, countygrf Essex, State of-Massachusetts, have invented an Improvement in Automatic Fire-Alarms, of which the fol- I lowing description, in 'connection 'with the accompanying ',dra'wing, is. a specification, likejcharacters on the ydrawing representing like partsf s n,

This invention relates' to automatic lire l`a larm.s and p'artihlarly tofthe detector mechanism hy whichthe re alarm signal Will be automatically sent lin when tire con-u ditions arise. j p

-Onefobject Iof the inventlon 1s to provide 'a differentiating detector device which will ldiii'erentiate between a rise ofwtemperature vdue to-tire conditions and a rise of temperature due to other causes, andwhich will be.

come operative to sou-nd the alarm `whenever tire conditions arise, but which will be inoperative for this purpose when an excessive. temperature arises in the locality where the device is located, provided such excessiver temperature is not the result/of fire conditions.

Another object ofthe iivention'is to ,pro-4 vide a fire alarm system whichv will differentiate between afalse alarm and a true alarm, and also-to provide a lire alarm apparatus which willv give indication ,when

the circuit of the detectorfdevice is open or broken, and votherwise to improve tire alarm apparatus, all as will 'be more fully hereinafter setforth.-`v

"Il accomplish these various objects by employing. as. my detector a device in the na-v ture of a diiierentiatin'g thermoelectric `loat- -tery uwhich 'isV connected to ,av relay that opcrates two circuits and is' constructed to causeathe relay to close one circuit when lire conditions arise and to close the other circuit when it issubjeted to a. rise of temperature Vdue to anabnormal cause, such, for instance, as an attempt;` to send in a false alarm. As -is wellknown to those skilled inthe art, athermo-electric battery has the capability'of generating a current in one direction when the temperature of one set of the junctions thereof is raised relative @to thatof .the-eter junctions 'and of=de veloping' arfcurrenA in. the other direction j when temperature of the lirst-narned l. junctionslis' lowered relative totha'tl oft-theother junctions., If, however, all the june.-l

tions are of the same temperature no current is generated. The thermo-electric battery in my invention is so sustained rela-- .tive to the wall or ceiling of the room in which it is placed that it will be uninfluenced by the temperature of the wall or ceiling and will be influenced lonly by the temperature of the atmosphere. `The terminals of one'set are situated so that they are vice such as would be causedb'y applying va lighted match thereto. Hence with this arrangement ,a current in one direction will be generated by the detector device when it is subjected to a rise of temperature due to tire conditions while a current in the other vdirection will be generated when it is subjected to a rise of temperature due to some abnormal condition.` The circuit of the detector lis connected' to a relay arranged to close either one of two circuits, depending upon the direction of the current generated by the detector. Eachl circuit will have a suitable signal therein so that by observing.

the. operation of the signal, it can be determined whether the detector isbeing subjected to a rise of temperature due to ir'e conditions or to a rise of temperature due to some other cause.` 'The device is thus a differentiating detector.

In order to give an understanding ofniy invention` I have illustrated in the vdrawings a selected ernoodiment thereof which will now be described, after which the novel features will be pointed out in the appended claims. f j 'Figure 1 is a vertical section through the thermo-electric element of my apparatus;

Fig. 2 is a bottom plan view of the therl ino-electric elementv with the protecting cover 19 removed, said view'also showing the relay and wiringfconnections.

y The circuit by or through which the alarm is sounded is indicated at 1, said Acircuit including a retu'rnr.wire 25. I have not shown `herein the details of a fire 'alarmboX, as this may be of' any [suitable construction adapted to be rend-ered operative to send in the alarm when the circuit 1 is closed, but l have illustrated diagrammatically at al a city tire alarm box to which the circuit 1, is connected, and it will be understood that when' said circuit 1, 251is closed, the box Ll-'l will be actuated to send an alarm to headquarters over the usual signal circuit 42. A ire alarm box adapted Afor such use is illustrated in my Patent No.

1,194,571, August 15, 1916. The circuit 1 is shown as havingtwo normally-open connis no current in Athe coil 5, then said coil and its pointer 3 will assunie`a neutral position. lf the current. ows through said coil in one direction, then the coil will be turned about its axis to swing the pointer 3 toward the Contact 2, while if current Hows from the coil in the opposite direction, said coil will be turned oppositely to swing its pointer away. from the contact 2.

The coil 5 of the relay is connected in a circuit 8 whichV leads to the thermo-electric element of my apparatus. This thermoelectric element is inthe nature of a thermoelectric battery composed of a plurality of thermo-electriccouples, each of which vcomprises two members'9 and 10 of different metals which are connected at the junctions 11 and. l2. -These electric couples are arranged in series as usual inv a thermo-electric battery, and are sustained in a plate 13 of insulating material, the mem-bers 9 and 10 of each couple extending` transversely through the plate so that theljunctions y12 are situated above the plate, while the juno! tions 11 are situated below the plate.` This supportingplate l13 with the thermo-electric couples secured thereto'i's sustained' by a base-piece 14, preferably of insulating material, which is adapted to be screwed toa ceiling 15 or to a wall or any other suitable support. The plate 13 is so secured to the base 14 that the junctions 12 are'spaced from said plate and ceiling and are exposed freely tu 'the atmosphere. lVhile .any suitable way c" supporting the plate 13 from the base 14 nught be employed, I have herein shown the plate as secured to a plurality of posts 16 which in turn are secured to the-base 14. These posts are shown as hollow and they are secured to thebase by means of screws 17 which extend through the base and screw into one end of the hollow posts. The plate 13 is secured to the'posts by other screws 18 which extendl through the plate and screw into the lower end of the posts. With this construction the upper junctions 12 of the thermo-electric 'battery are situated between the plate 13 and the base 1-l,and are' spaced from both the base and the wall 15. Moreover, they are freely exposed to the atmosphere and are Subj ect to the full eii'ect of any atmospheric temperature changes.

Means are provided for protecting the lower junctions 11 that arev situated below the plate 13' from the full eifect of rapid temperature changes.. This may be done -in various ways, and as one simple construction, I have shown a cap or cover 19 which is secured to the plate 13 and inclosesv the junctions 11. The protecting cap or cover 19 may be made of metal, rubber, fiber or any suitable material. l

The opposite 'ends of the battery are connected to .two terminals 2O and 21 to which areconnected the two sides *ofi the circuit 8 having vthe operating 'relay 7 therein;

The operation of the device as thus far described is as follows:

So long as the atmospheric ,temperature in the locality of the thermo-electric element remains substantially constant or isv subjected to slow variation, the two sets of junctions lland 12 will have substantially the same temperature, 'and consequently nol current will be generated in the circuit 8. As a result, the corl 5 will remain 1n its central position :and the cont-act 3 will be sep-' 100 arated from the contact .2. If, however, there should be va rapid rise in atmospheric temperature, such, for instance, as would result in the case of a fire, the exposed junctions 12 will immediately feel the effect of 105 such change of temperature, and the temperature of said junctions will rise accordinglyl Since the other junctions 1-1 are protected bythe protecting cover-19, they will be influenced only gradually by the sudden rise in temperature. In other words, the eil'ect of the rapid rise in'temperature on the junctions 11 is retarded. Consequently, the exposed junctions 12 will soon acquire a ternperature greater than the protectedjunctions 11, and this difference in temperature will generate a current in the circuit 8. The' current thus generated Hows through the coil 5 in a direction to cause said coil to turn into a position to close the contact 8 against 120 the contact 2, thus closing the circuit 1, 25, with the result that the. box l1 will oper ate to send the alarm. The protection afforded bv the rcover 19 is lintended to be simply suficient to protect the junctions 11 125 against the infiuence of a rapid rise in temperature, such as would be caused by ire conditions. blit not to protect said j unctions against the influence of a slow or gradual rise inl temperature. lf, therefore, the temperature in the locality of the thermo-electric element rises gradually or slowly, the

. vrelative temperature of the twoy sets of junctions v1l and 12 will remain approximately the same, and as a result there will not bev posts 16 andwhich form with the posts a sort of grid to prevent any foreign substance from ,entering between the plate 13 and the base 14.

llt sometimes happens thatmischievous or malicious persons will attempt to send in a false fire alarm by applying a match or some otlielarticial heat to the thermostatic element of anvautomatic ltire alarm system. My apparatus is so constructed that 1f any person does maliciously apply a match to the thermo-electric element with the intention to send in a false alarm, the relay will operate to indicate the` fact that the device has been tampered with, but will not send in the alarm. A person attempt-ing thus to send in' a false alarm would naturally apply the match or other heating means to the bottom of the thermo-electric element, that is, .to the protecting plate 19. If this is done', the heat will be transmitted through said plate to the junctions 11 and the temperature of the junctions 11 will thus be raised over that of the junctions 12. This will cause a current to flow in the circuit 8 in a direction opposite to that in which it flows when the junctions 12 are 'at a higher ten'iperature than the junctions 111, and lsuch current will cause the coil 5 to turn ina direction to move the contact 3 away from the contact 2. I have provided herein an additional contact 23 situated on the opposite side of the contact. '3 from the contact 2 so that when the indicator contact 3 swings to the right, Fig. 2,

it will engage thel Contact This contact 23 is in a circuit 24 leading to any suitable signal apparatus other than the fire alarm apparatus and which will preferably be situated at headquarters. The circuit 24 may be connected to the return 25.v 1f, therefore, a person attempts to send ina false alarm by applying heat to the underside of the thermo-electric element, the result will be the closing of the circuit 2-1 and the indication at headquarters ofthe fact that. an attempt had bcen made to send in a false alarm. My thermo-electric element isJ therefore, so constructed that it will be affected in one way by a sudden rise of temperatura` in the space surrounding said element, such, for instance, as would be due to fire conditions, and will be affected in another way by'a sudden rise in temperature locally aplplied to said element, such, for instance, as would result from the application of a lighted match thereto'. The unctions 12 are influenced freely by sudden rise in temperature in the space-surrounding the thermoelectric element, but4 since they are situated between the plate 13 and the base 14 they areprotected from the full effect of a local rapid rise in temperature, such as would result from applying'a lighted match to the device.

vThe junctions 11, on the other hand, are protected from the rapid rise in temperature in the space surrounding the element, but are not protected from the local rapid rise in temperature. y

I have also provided herein means whereby a suitable indication will be made if the circuit 8 becomes open by the breaking of a wire or otherwise. This is herein accom-v plished by placing across said circuit 8 a shunt circuit 26 having therein a relativelyhigh resistance 27 and also a relatively-small source of electricity, such, for instance, as

a single dry cell 28. The resistance of the circuit 8 is relatively low and the high resistance 27 will prevent` any of the currentgenerated by the thermo-electric device from flowing through the shunt circuit 26, so that the presence of the shunt circuit does not interfere 4with the operation of the device.

Moreover, owing' to the high resistance 27 the amount of current which is impressed on the circuit 26 by the dry cell 28 willbe eX- ceedingly small, and so long `as the circuit is closed, the greater part of such exceedingly; small current will flow through the thermo.- electric element rather than through the coil owing to the greater resistance of the'coil. The device is so adjusted that the amount of current from the battery 28 Whichis thus normally impressed on the. coil 5 is insuf- Vficient to affect the relay so long as' the cir-- cuit 8 is closed. The cell 28fis so connected in the circuit that the, current generated thereby tends to oppose the current `generated by the thermo-electric element when the junctions 12 are at a higher temperature than the junctions 11 and tends to flow through the coil v5 in a direction to cause the contact 3 to swing toward the contact 23., If. the circuit Sshould become broken between the shunt circuit 26' and the thermo-electric element, then all the current generated by the battery 28 will be impressed on the' .coil

4In actual practice the relay 7 will be made Lilli very sensitive so'that it will respond to an exceeding'l #small current. Fig. 2 of the drawings isintended to illustrate a relay diagrammatically without any intention of.

t'wo heads are drawn together slightly and,`

the resiliency of them will tend to hold the wire taut and thus insure a good electrical connection. p

yI claim:

1. In fire alarm, the combination with a differentiating thermo-'electric battery comprising a plurality of connected thermo-electric couples and means by which the junctions of one set are freely `exposed to rapid temperature.changes .in the space surround: ing the thermo-electric element but are protected against.. local rapid temperature changes and the junctions of the other set are protected against rapid temperature changes inthe space` surrounding the thermo-electric element but are influenced freely by' a rapid local temperature change whereby a current will be generated in one direction when the device is subjected to a rise of temperature due to lire conditions and will be generated in the other direction when subjected to a localized rise of temperature, of two indicating circuits, and means to close one circuit when the current generated by said thernxoelectr'ic clement flows in one direction and the other circuit when said current Hows in the other direction.

2. In a detector device for fire alarm apparatus, the combination with a base member adapted to be secured to a wall or cylinder, of a supporting plate Sustained thereby, but separated therefrom, a plurality of connected thermo-electric' couples sustained by said supporting plate, the junctions 'which are situated between the plate and n the base bein-g exposed to the influence of rapid temperature changes, and meansprotecting the set of junctions on the outside of said supporting plate from the infiuence of rapid temperature changes.

3. In a detector .device for fire alarm ap* paratus, the combination with 'a base member adapted to be secured to a wall or cylinder, of a supporting plate sustained thereby, but'separated therefrom, a plurality of connected thermo-electric couples sustained by said supporting plate, the junctions which are situated between the plate and the base 4;. A thermo-electric element for fire alarm systems comprising a Vplurality of connected thermo-electric couples having two sets of junctions, means for protecting the junctions of one set against a local rapid rise of temperature while'permitting said junctions to be freely influenced by a' rapid rise of temperature in the space surrounding said element and for protecting the other set of junctions from said latter sudden rise in temperature while permitting lthe rfirst-named' set of junctions to be influenced freely by the local rapid rise of temperature.

5. Ina `lire alarm apparatus, the combina-- tionwith a diierentiating thermo-electric battery comprising a plurality of connected thermo-electric couples, means to protect the junctions of one set from rapid temperature changes in the space surrounding the battery while permitting said junctions to be freely ai'lected by a rapid rise in temperature local;

ized Iclosely adjacent to said battery, and to protect the junctions of the other set fromI such localized rapid rise of temperature without al'ecting the influence thereon -fo the rapid rise in temperature 1n the space surrounding the battery, of two circuits,

means to close one circuit when current is developed in one direction in said battery and the other circuit when current is developed in the other direction in said bat'- tery, a city lire alarm box connected to one or' said circuits and adapted to be actuated by the closing thereoiu to send an alarm to headquarters, and a signal connected to and l actuated by the closingof the other circuit'.

6. In a lire alarm apparatus, the combif nation with a dilerentiating thermo-electric battery comprising a plurality of connected i thermo-electric couples and means by `which said battery will develop current in one direction when it is subjected to a rise of temperature due to lire conditions, and in the other direction when subjected to a rapid -rise of temperature localized closely adja`l cent said battery, two indicating circuits, means to close one circuit when the battery develops current in one direction and theother circuit when it develops current in the other direction, a city ire alarm box connected to -one circuit to bel actuated by the closing thereof to send an alarm to headquarters, and a signal device in the other circuit. i

In testimony ulfhcreof, I have Signed myl name to this specification.

FREDERIC-K A. swAN. 

